"[I'm] Balthazar Horowitz, but you can just call me the Ball pit Kid."
Balthazar Horowitz, also known as the Ball Pit Kid, is a young boy with dark blond hair. In contrast to Phineas and Ferb, he is an average boy. He has made a large amount of appearances in the show.
He has been seen with a woman wearing a dark blue shirt and a blue headband. She has been seen taking notes during an interview and may be a reporter. She and a shorter girl in a lighter blue shirt have been seen accompanying Pinhead Pierre actress.
- He is voiced by Django Marsh, the son of co-creator Jeff "Swampy" Marsh.
- Due to his voice actor, Django Marsh, going through puberty, Balthazar's voice has gotten much deeper as the show has progressed.
- He shares his first name with the Milo Murphy's Law character Balthazar Cavendish.
|"Toy to the World"||Buys a Perry the Inaction Figure.|
|"Bowl-R-Ama Drama"||Is at the fair seeing the Amazing Penguin Man during the end credits.|
|"Put That Putter Away"||Is going down the slide at Phineas and Ferb's miniature golf course.|
|"Out of Toon"||Is in the Pinhead Pierre opening.|
|"Interview With a Platypus"||Is at the park when Candace runs by him, chased by the animals.|
|"Oh, There You Are, Perry"||Participates in singing "Come Home Perry".|
|"No More Bunny Business"||Phineas and Ferb use their x-ray specs to find and retrieve him from the ballpit he has gotten lost in (hence his nickname). Oddly, when Ferb pulls him out, he has brown hair and is wearing a black shirt, brown shorts, and mahogany shoes and hat, similar to Buford Van Stomm's color scheme. But in the very next shot, he has his normal color scheme.|
|"Fireside Girl Jamboree"||Is one of the customers to receive the Fireside Girl Cupcakes tossed by Candace during the song .|
|"Finding Mary McGuffin"||Is in the crowd at the baseball game Heinz and Vanessa were attending in flashback during "Not So Bad A Dad".|
|"Just Passing Through"||Claps Candace's raised hand when she gets herself stuck in the porta-potty door.|
|"I Was a Middle Aged Robot"||Sees Agent P, in the Lawrence robot, placing his "consumed" pies out from the robot's posterior ("Ewwww!"). He later sees Carl talking to Agent P after they bring Lawrence to the picnic. At the very end, he comes upon Perry again and says, "Hey, don't I know you from somewhere?"|
|"The Lizard Whisperer"||Is in the crowd that gathers during Ferb's speech.|
|"The Lemonade Stand"||Buys lemonade at Phineas and Ferb's lemonade stand and says it's the best lemonade he's ever had.|
|"Phineas and Ferb: Summer Belongs to You!"||Is in the big cast shot at the end of the closing song.|
|"Run, Candace, Run"||Was listening to the book Candace was reading at the library.|
|"Phineas' Birthday Clip-O-Rama!"||Sees Candace with a CD, a flower, a flange tuner, and a hat on her. He also asks for her autograph.|
|"The Belly of the Beast"||He's at the Danville Harbor Festival when Captain Squint performs The Shark of Danville Harbor|
|"Magic Carpet Ride"||He's eating Chinese food at the Better Panda Restaurant.|
|"Meatloaf Surprise"||He and other kids chase Buford after he destroyed the Meatloaf festival's bounce house.|
|"A Real Boy"||Observes a lizard leaping around Jeremy's feet.|
|Phineas and Ferb the Movie: Across the 2nd Dimension||Seen buying ice cream with Pedro.|
|"Quietest Day Ever"||Seen during the song I'm Handsome.|
|"Backyard Hodge Podge"||Seen with his parents exiting the ophthalmologist. Is referred to by name for the first time.|
|"Great Balls Of Water"||Seen with some kids playing "who's it".|
|"Knot My Problem"||Seen riding a pogo-stick and coming across Perry again.|
|"Happy Birthday, Isabella"||Attends Isabella's birthday party.|
|"Love at First Byte"||Balthazar is seen at the block party watching the dance. He gets a balloon fedora from Perry.|
|"Troy Story"||He reveals his name on-screen as well as his nickname and participate in Phineas and Ferb's Troy representation.|
|"The Inator Method"||Seen with Phineas, Ferb and their friends.|